A 2-(p-alkylphenyl)pyridine compound is useful as a pharmaceutical intermediate; for example, as a synthesis intermediate for 4-(pyridin-2-yl)benzaldehyde which is an intermediate for an anti-HIV drug (A) of the following formula disclosed in WO97/40029. ##STR1##
In addition, Japanese Patent Unexamined Publication No. 95157/1991 discloses a butenoic acid derivative as an agent for the therapy, prophylaxis and amelioration of ischemic heart disease. This butenoic acid derivative is synthesized via 4-(pyridin-2-yl)benzaldehyde. The above-mentioned 4-(pyridin-2-yl)benzaldehyde is synthesized by, for example, a method comprising brominating 2-(p-tolyl)pyridine and reacting the resultant compound with hexamine.
The production method of 2-phenylpyridine compound is disclosed in, for example, Heterocycles, vol. 18, 117-122 (1982), wherein 2-bromopyridine and phenylzinc chloride are reacted using Pd(PPh.sub.3).sub.4 as a catalyst to give 2-phenylpyridine in an 89% yield. Moreover, the production method of 2-(p-alkylphenyl)pyridine compound is disclosed in, for example, Tetrahedron Letters, vol. 36, No. 50, 9085-9088 (1995), wherein a 2-arylpyridine compound (e.g., 2-(p-tolyl)pyridine) is obtained via an organic tin compound in a 60% yield again using Pd(PPh.sub.3).sub.4 as a catalyst. Tetrahedron, vol. 54, 1289-1298 (1998) discloses that a 2-arylpyridine compound can be obtained by reacting arylzinc halide obtained electrochemically and 2-halopyridine using a nickel complex catalyst. However, the catalysts used in the production methods of these known 2-(p-alkylphenyl)pyridine compounds are expensive. Thus, there has been a demand of a production method of a 2-(p-alkylphenyl)pyridine compound that permits economical, facilitated and industrial production.
It is therefore an object of the present invention to provide a method of producing a 2-(p-alkylphenyl)pyridine compound economically, easily and industrially.